Terminal with charging circuit and device thereof

ABSTRACT

A terminal and a device are provided. The terminal includes a charging interface and a first charging circuit. The first charging circuit is coupled with the charging interface, and is configured to receive an output voltage from the adapter via the charging interface and apply the output voltage to both ends of multiple cells connected in series in the terminal to charge the multiple cells.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. Ser. No. 15/691,961, filed onAug. 31, 2017, which claims priority to International Application No.PCT/CN2016/101943, filed on Oct. 12, 2016 and International ApplicationNo. PCT/CN2016/101944, filed on Oct. 12, 2016, the contents of all ofwhich are herein incorporated by reference in their entities.

TECHNICAL FIELD

The present disclosure relates to the field of electronic equipment, andparticularly to a terminal and a device.

BACKGROUND

Terminals, specifically terminals such as smart phones are becomingincreasingly popular with consumers; however, mobile terminals generallyconsume a lot of power and so need to be frequently charged.

In order to improve the charging speed, a feasible solution which uses alarge current for charging of the mobile terminal has been proposed. Thegreater the charging current, the faster the charging speed of themobile terminal, but the mobile terminal heat problems will be moreserious.

Therefore, how to ensure the charging speed under the premise ofreducing the terminal heat has become an urgent problem to be solved.

BRIEF DESCRIPTION OF DRAWINGS

To better illustrate the embodiments of the disclosure, a briefdescription of the accompanying drawings for use with the illustrationof the embodiments is provided below. It is evident that the drawingsdescribed below depict merely some embodiments and those of ordinaryskill in the art can obtain other drawings based on the arrangementsillustrated in these drawings without making inventive efforts.

FIG. 1 is a structural diagram illustrating a terminal according to anembodiment of the present disclosure.

FIG. 2 is a structural diagram illustrating a terminal according toanother embodiment of the present disclosure.

FIG. 3 is a structural diagram illustrating a terminal according tostill another embodiment of the present disclosure.

FIG. 4 is a structural diagram illustrating a terminal according tostill another embodiment of the present disclosure.

FIG. 5 is a waveform diagram of a pulsating direct current (DC)according to an embodiment of the present disclosure.

FIG. 6 is a structural diagram illustrating a terminal according tostill another embodiment of the present disclosure.

FIG. 7 is a structural diagram illustrating a terminal according tostill another embodiment of the present disclosure.

FIG. 8 is a structural diagram illustrating a device according to anembodiment of the present disclosure.

FIG. 9 is a structural diagram illustrating a terminal according tostill another embodiment of the present disclosure.

FIG. 10 is a structural diagram illustrating a terminal according tostill another embodiment of the present disclosure.

FIG. 11 is a flow chart illustrating a quick charging process accordingto an embodiment of the present disclosure.

DETAILED DESCRIPTION

Terminal

The term “terminal” as used in the embodiments of the present disclosuremay be, but is not limited to, a device configured to be coupled via awired line and/or receive/transmit communication signals via a wirelessinterface. Examples of the wired line may include, but are not limitedto, at least one of a public switched telephone network (PSTN), adigital subscriber line (DSL), a digital cable, a cable used for directconnection, and/or another data connection line or network connectionline. Examples of the wireless interface may include, but are notlimited to, a wireless interface for a cellular network, a wirelesslocal area network (WLAN), a digital television network such as adigital video broadcasting-handheld (DVB-H) network, a satellitenetwork, an AM-FM broadcast transmitter, and/or another communicationterminal.

A terminal configured to communicate via a wireless interface may bereferred to as a “wireless communication terminal”, a “wirelessterminal”, and/or a “mobile terminal”. Examples of a mobile terminal mayinclude, but are not limited to, a satellite or cellular telephone, apersonal communication system (PCS) terminal capable of combiningcellular radio telephone and data processing, fax, and datacommunication capabilities, a personal digital assistant (PDA) equippedwith radio telephone capacity, pager, Internet/Intranet access capacity,Web browser, notebook, calendar, and/or global positioning system (GPS)receiver, and a conventional laptop and/or a handheld receiver oranother electronic device equipped with radio telephone capacity.

The term “terminal” as used in the embodiments of the present disclosuremay include a power bank; the power bank can accept the charging from anadapter, so as to store energy and provide energy for other electronicdevices.

Technical solutions of embodiments of the present disclosure will bedescribed below clearly and completely with reference to theaccompanying drawings.

In the related art, a terminal such as a mobile terminal generally has asingle cell. When the single cell is charged with a large chargingcurrent, heat of the mobile terminal can be serious. In order toguarantee the charging speed of the terminal and alleviate the heat inthe charging process thereof, a battery structure inside the terminal ismodified, in which multiple cells (that is, a plurality of cells)connected in series and can be directly charged are introduced.Technical solutions of embodiments will be described in detail withreference to FIG. 1 .

FIG. 1 is a structural diagram illustrating a terminal according to anembodiment of the present disclosure. As illustrated in FIG. 1 , aterminal 10 may include a charging interface 11 and a first chargingcircuit 12 coupled with the charging interface 11. The first chargingcircuit 12 can be configured to receive an output voltage from anadapter. The first charging circuit 12 can be further configured toapply the output voltage directly to both ends of multiple cells 13which are connected in series in the terminal, so as to charge theplurality cells 13 directly. In FIG. 1 , two single cells connected inseries are illustrated and the present disclosure is not limited theretohowever, for example, three or even more cells can be arranged in thecircuit.

The term “directly” used herein either individually or sometimes go withthe terms “apply”, “output current”, and/or “output voltage”, may meanthat, the output voltage and the output current from the power adaptermatches current voltage of the multiple cells, or may mean that, theoutput voltage from the adapter can be applied to both ends of themultiple cells for charging without voltage converting.

In the related art, the output voltage of the adapter are not directlyapplied to both ends of a cell, instead, it is necessary to convert theoutput voltage of the adapter through a number of conversion circuitsand then apply the converted voltage to both ends of the cell forcharging. For example, the output voltage of the adapter is about 5Vgenerally. After receiving the 5V output voltage of the adapter, theterminal will use a Buck circuit to perform a step-down conversion,alternatively, the terminal may use a Boost circuit to perform a step-upconversion; thereafter, the terminal can apply the converted voltage toboth ends of the cell.

Usage of the conversion circuit may cause the heat of the terminal to beserious and cause power loss of the adapter either. In order to solvethe heat problem caused by the conversion circuit and reduce the powerloss, in embodiments of the present disclosure, the multiple cells 13are directly charged via the first charging circuit 12.

“Direct-charge” means the output voltage from the adapter are directlyapplied or introduced to both ends of the multiple cells 13 forcharging, the output voltage of the adapter need not be converted by theconversion circuit and energy loss caused by a conversion process can beavoided. In the charging process through the first charging circuit 12,in order to adjust a charging voltage in the first charging circuit 12,the adapter can be designed as an intelligent adapter and the conversioncircuit for the charging voltage can be built inside the adapter, assuch, conversion of the charging voltage can be completed by theadapter. The burden of the terminal can be reduced and theimplementation of the terminal can be simplified.

The direct-charge scheme can reduce the heat generated in the terminalto a certain degree; however, when the output current of the adapter istoo large, such as between 5 A and 10 A, the heat of the terminal maystill be serious and raise safety risks. In order to guarantee thecharging speed and further relieve the heat of the terminal, accordingto implementations of the present disclosure, the battery structureinside the terminal is modified and multiple cells connected in seriesare provided. To achieve the same charging speed, compared with asingle-cell scheme in the related art, the charging current required forthe multiple cells is 1/N of the charging current required for a singlecell (N represents the number of cells serially connected inside theterminal). In other words, compared with the single-cell scheme in therelated art, the technical solution of the present disclosure cangreatly reduce the magnitude of the charging current under the premiseof ensuring the same charging speed, thereby reducing the heat generatedin the terminal during a charging process.

For example, for a single cell of 3000 mAh, a charging current of 9 Awill be required to achieve a charging rate of 3 C. Two cells of 1500mAh can be connected in series to substitute the single cell of 3000 mAhto obtain the same charging speed and reduce the heat generated whencharging the terminal. As such, a charging current of about 4.5 A canachieve a charging rate of 3 C, and compared with a charging current of9 A, the heat caused by the charging current of 4.5 A is significantlylower.

Since the multiple cells 13 is charged directly via the first chargingcircuit 12, the output voltage received by the first charging circuit 12from the adapter toned to be larger than the overall voltage of themultiple cells. The operating voltage of a single cell is about3.0V˜4.35V generally, based on this, for dual cells connected in series,the output voltage of the adapter can be set as greater than or equal to10V.

The type of the charging interface 11 mentioned herein is notparticularly limited. For example, it can be a universal serial bus(USB) interface or a TYPE-C interface. The USB interface can be a normalUSB interface or a micro USB interface. The first charging circuit 12may charge the multiple cells 13 via a power line in the USB interface.The power line in the USB interface can be a VBus line and/or groundline in the USB interface.

The type of the terminal mentioned herein is not particularly limited.For example, it can be a smart phone, a pad, and the like.

The multiple cells 13 in the embodiments can be cells with the same orsimilar specification or parameter. Cells with the same or similarspecification can facilitate management, meanwhile, the overallperformance and service life of the multiple cells 13 composed of cellswith the same or similar specification or parameter can be improved.

It will be appreciated that the multiple cells 13 connected in serieswith each other is capable of dividing the output voltage of theadapter.

Currently, the terminal (or devices/chips within the terminal) ispowered via a single cell. According to embodiments of the presentdisclosure, multiple cells connected in series are provided. The overallvoltage of the multiple cells is higher and is therefore not suitable topower the terminal (or devices/chips within the terminal) directly. Tosolve this problem, a possible implementation is to adjust the operatingvoltage of the terminal (or devices/chips within the terminal) such thatthe terminal is capable of being powered via multiple cells. Thisimplementation however changes the terminal a lot and costly.Embodiments of the present disclosure, which aims to address the issueof how to power the terminal via the multiple cells, will be describedbelow in detail.

As one implementation, as illustrated in FIG. 2 , the terminal 10 mayfurther includes a step-down circuit 21 and a power supply circuit 22.The step-down circuit 21 has input ends (for example, two input ends)and an output end. The input ends of the step-down circuit 21 may becoupled with both ends of the multiple cells 13 and is configured toconvert the overall voltage of the multiple cells 13 into a firstvoltage V₁, where a≤V₁≤b, and a represents the minimum operating voltageof the terminal 10 (or devices/chips within the terminal 10), brepresents the maximum operating voltage of the terminal 10 (ordevices/chips within the terminal 10). The power supply circuit 22 iscoupled with the output end of the step-down circuit 21 and isconfigured to power the terminal 10 based on the first voltage V₁.

On the basis of the embodiment of FIG. 1 , the step-down circuit 21 isprovided in the embodiment as illustrated in FIG. 2 . When the terminal10 is in an operating state, the overall voltage of the multiple cells13 will be stepped down via the step-down circuit 21 to obtain the firstvoltage V₁, the amplitude of which is between the minimum operatingvoltage and the maximum operating voltage of the terminal 10 andtherefore can be used to power the terminal directly, and consequently,the issue of how to power the terminal with the multiple cells can beaddressed.

The overall voltage of the multiple cells 13 varies with the power ofthe multiple cells 13. Therefore, the overall voltage of the multiplecells 13 can be the current overall voltage of the multiple cells 13.For example, the operating voltage of a single cell can be between3.0V˜4.35V. Suppose the multiple cells 13 include two single cells andthe current voltage of each of them is 3.5V, the overall voltage of theforegoing multiple cells 13 will be 7V.

For a single cell, the operating voltage thereof can be in the range of3.0V-4.35V for example, and in this case, a=3.0V, b=4.35V. To guaranteea normal power supply voltage in the devices within the terminal, thestep-down circuit 21 may reduce the overall voltage of the multiplecells 13 to any value in the range of 3.0V-4.35V. The step-down circuit21 may be implemented in a variety of ways, for example, a Buck circuit,a charge pump, or the like.

In order to simplify the structure of the circuit, the step-down circuit21 can be a charge pump, through which the overall voltage of themultiple cells 13 can be reduced to 1/N of the current overall voltage,where N represents the number of cells constituting the multiple cells13. A traditional Buck circuit includes switches, inductors, and otherdevices and has a relatively large inductance loss, and stepping downwith the Buck circuit will result in a relatively large power loss inthe multiple cells 13. Compared with the Buck circuit, the charge pumpmainly uses a switch(s) and a capacitor(s) for stepping down, in whichthe capacitor basically do not consume extra energy and therefore,circuit loss caused by a step-down process can be reduced in case thecharge pump is used. The switch inside the charge pump controls thecharging and discharging of the capacitor in a certain way, such thatthe input voltage can be reduced by a certain factor (1/N in someembodiments) to obtain a desired voltage.

As another implementation, as illustrated in FIG. 3 , the terminal 10may include a power supply circuit 32. Compared with the structureillustrated in FIG. 2 , the step-down circuit is removed from FIG. 3 andthe power supply circuit 32 can be coupled with the multiple cellsdirectly. In detail, the power supply circuit 32 may have input ends(such as two input ends) coupled with both ends of any single cell ofthe multiple cells 13 and can power devices inside the terminal 10 onthe basis of the voltage of the single cell connected therewith.

It should be noted that, voltage ripple may occur after the step-downprocess of the step-down circuit and may affect the power quality of theterminal. According to embodiments of the present disclosure, the supplyvoltage is drawn directly from both ends of a certain single cell of themultiple cells to power devices inside the terminal. As the outputvoltage of the cell is relatively stable, it is possible to address theproblem of how to supply power via the multiple cells while maintainingthe power supply quality of the terminal.

Further, on the basis of the embodiment of FIG. 3 , FIG. 4 furtherillustrates a terminal 10 which additionally includes an equalizationcircuit 33. The equalization circuit 33 is coupled with the multiplecells 13 and is configured to equalize the voltage among each cell ofthe multiple cells 13.

After using the power supply scheme as illustrated in FIG. 3 , a cell(hereinafter referred to as “main cell” and the remaining cell(s) willbe referred as “secondary cell”) that powers devices within the terminalwill continue to consume power, this may cause the voltage between themain cell and secondary cells to be unbalanced (i.e., voltageinconsistency). The voltage imbalance occurred in the multiple cells 13may reduce the overall performance and service life of the multiplecells 13. Besides, the voltage imbalance occurred in the multiple cells13 makes it difficult to manage the multiple cells 13 uniformly. Takethe above into consideration, the equalization circuit 33 is used toequalize the voltage among each cell of the multiple cells 13, improvethe overall performance of the multiple cells 13, and facilitate theuniform management of the multiple cells 13.

The equalization circuit 33 can be implemented in various ways. Forexample, a load can be connected at both ends of a secondary cell toconsume the power of the later, as such, the power of the secondary cellcan be consistent with the main cell, and the voltage of the secondarycell can be consistent with the main cell. Alternatively, the secondarycell can be used to charge the main cell until the voltage of these twobecomes the same.

As the output power of the adapter becomes larger, it is likely to causelithium precipitation when charging cells inside the terminal, reducingthe life of the cell.

As one implementation, the first charging circuit 12 may be furtherconfigured to receive an output current from the adapter. In order toimprove the reliability and safety of the cell, in some embodiments, itis possible to control the adapter to output a pulsating direct current(DC) (also known as unidirectional pulsating output current, current ofa pulsating waveform, or current of a steamed-bun shaped waveform).Since the first charging circuit 12 can be used for direct charging, thepulsating DC output by the adapter can be used to charge the multiplecells 13 directly. As illustrated in FIG. 5 , the current magnitude ofthe pulsating DC is periodically changed; compared with aconstant-current, the pulsating DC is capable of relieving lithiumprecipitation of the cell and improving the service life thereof.Besides, compared with the constant-current, the pulsating DC can reducethe probability and strength of arcing of a contact(s) of the charginginterface and prolong the service life of the charging interface.

There can be several ways to set the output current of the adapter as apulsating DC. For example, a secondary filter circuit of the adapter canbe removed, and an output current of a second rectifier circuit (theoutput current of the rectifier circuit is the pulsating DC) can be usedas the output current of the adapter directly.

Similarly, in some embodiments, the output voltage received by the firstcharging circuit 12 from the adapter can be a voltage of a pulsatingwaveform, which is also known as unidirectional pulsating output voltageor a voltage of a steamed-bun shaped waveform.

Alternatively, in some embodiments, the output current received by thefirst charging circuit 12 from the adapter can also be an alternatingcurrent (AC) (for example, there is no need for rectification andfiltering inside the adapter, and mains supply can be output directlyafter being stepped down). The AC is also capable of relieving lithiumprecipitation and improving the service life of the cell.

Alternatively, in some embodiments, the first charging circuit 12 isoperable in a charging mode of constant-current mode. It should be notedthat, the constant-current mode means that the charging current remainsconstant over a period of time rather than mean that the chargingcurrent always remains constant. Actually, in the constant-current mode,the first charging circuit 12 can adjust the charging current of theconstant-current mode in real time according to the current voltage ofthe multiple cells to achieve a multi-stage constant-current. Further,if the output current received by the first charging circuit 12 from theadapter is the pulsating DC, by that the first charging circuit 12 isoperable in a charging mode of constant-current mode, it means that thepeak value or the average value of the pulsating DC remains constant fora period of time. If the output current received by the first chargingcircuit 12 from the adapter is the AC, by that the first chargingcircuit 12 is operable in a charging mode of constant-current mode, itmeans that the peak value or the average value of a forward current ofthe AC remains constant for a period of time.

In some embodiments, as illustrated in FIG. 6 , the multiple cells 13may be co-packaged in a battery 51. The battery 51 may further include abattery protection board 52 through which over-voltage/over-currentprotection, power balance management, power management, and otherfunctions can be achieved.

In one implementation, as illustrated in FIG. 7 , the terminal 10 mayfurther include a second charging circuit 61. The second chargingcircuit 61 can be coupled in parallel with the first charging circuit12. The second charging circuit 61 can be coupled between the charginginterface 11 and the multiple cells 13, that is, the second chargingcircuit 61 may have one end coupled with the charging interface and theother end coupled with one end of the multiple cells 13.

As illustrated in FIG. 8 , a device which has a structure similar tothat of FIG. 7 is also provided. The device is equipped with a charginginterface 11, a cell unit 15, a first charging circuit 12, and a secondcharging circuit 61. The cell unit 15 includes multiple cells connectedin series. The first charging circuit 12 is coupled with the charginginterface 11 and configured to receive an output voltage from a chargingdevice (such as a power adapter) and apply the received output voltagedirectly to both ends of the cell unit 15 for charging the multiplecells. The second charging circuit 61 is coupled in parallel with thefirst charging circuit 12. The second charging circuit 61 may beconfigured to receive the output voltage from the charging device viathe charging interface 11, step up the received output voltage, andapply the step-up output voltage to the both ends of the cell unit 15for charging the multiple cells. The first charging circuit 12 iscapable of being operated in a first charging mode, the second chargingcircuit 61 is capable of being operated in a second charging mode, andthe charging speed of the device in the first charging mode is greaterthan the charging speed of the device in the second charging mode. Thedevice can switch between the first charging circuit and the secondcharging circuit, that is, switch between the first charging mode andthe second charging mode.

As illustrated in FIG. 9 , the second charging circuit 61 illustrated inFIG. 7 or FIG. 8 may include a step-up circuit 62, which has one endcoupled to the charging interface 11 and the other end coupled to themultiple cells 13. The step-up circuit 62 can receive the output voltageof the adapter via the charging interface 11, step-up the output voltageof the adapter to a second voltage, and apply the second voltage to bothends of the multiple cells 13 for charging. The output voltage receivedby the second charging interface 61 from the adapter is less than theoverall voltage of the multiple cells; the second voltage is greaterthan the overall voltage of the multiple cells.

From the above, the first charging circuit 12 can charge the multiplecells 13 directly; this charging mode (that is, direct charging)requires the output voltage of the adapter greater than the overallvoltage of the multiple cells 13. For example, when two cells areconnected in series, assuming that the current voltage of each cell is4V, and the output voltage of the adapter is required to be at least 8Vwhen the first charging circuit 12 is used to charge the two cells.However, the output voltage of a conventional adapter is generally 5Vand therefore, it is impossible for the conventional adapter to chargethe multiple cells 13 through the first charging circuit 12. To becompatible with the charging mode provided by the conventional adapter,a second charging circuit 61 including a step-up circuit is provided.The step-up circuit can increase the output voltage of the adapter to asecond voltage that is greater than the overall voltage of the multiplecells 13, thereby addressing the problem that the conventional adaptercannot charge the multiple cells 13 connected in series with each other.

As long as the output voltage of the adapter is lower than the overallvoltage of the multiple cells 13, it is possible to be used to chargethe multiple cells 13 after being stepped up by the second chargingcircuit 61 and therefore, the voltage value of the output voltagereceived by the second charging circuit 61 from the adapter is notparticularly limited.

The form of the step-up circuit is not limited, which may be but is notlimited to a Booster circuit or a charge pump. In some embodiments, thesecond charging circuit 61 may adopt a conventional charging circuitdesign, that is, a charging management chip can be provided between thecells and the charging interface. The charging management chip canperform constant-voltage/constant-current control in a charging processand adjust the output voltage of the adapter per actual needs, such asstep-up or step-down (said differently, boost or buck). The embodimentof the present disclosure can utilize the step-up function of thecharging management chip to step up the output voltage of the adapter toa second voltage higher than the overall voltage of the multiple cells13. The switching between the first charging circuit 12 and the secondcharging circuit 61 can be realized by a switch or a control unit. Forexample, the terminal can be provided with a control unit inside. Thecontrol unit can flexibly switch between the first charging circuit 12and the second charging circuit 61 according to actual needs (such asthe type of the adapter).

Quick Charging Mode and Normal Charging mode

In one implementation, the first charging circuit 12 is operable in acharging mode which can be referred to as a first charging mode or quickcharging mode and the second charging circuit 61 is operable in acharging mode which can be referred to as a second charging mode ornormal charging mode. The charging speed of the terminal in the quickcharging mode is greater than the charging speed of the terminal in thenormal charging mode; the charging current of the terminal in the quickcharging mode is greater than the charging current of the terminal inthe normal charging mode for instance. The normal charging mode can beunderstood as a charging mode with a rated output voltage of 5V and arated output current less than or equal to 2.5 A. The quick chargingmode can be understood as a high current charging mode. The chargingcurrent of the quick charging mode can be greater than 2.5 A, up to 5-10A for example. In the quick charging mode, a direct charging mode isadopted, that is, the output voltage and the output current of theadapter can be applied to both ends of the adapter directly.

Furthermore, the charging interface 11 may further include a data line(not illustrated). As illustrated in FIG. 10 , the terminal 10 mayfurther include a control unit 71. The control unit 71 can performtwo-way communication with the adapter through the data line to controlthe charging of the multiple cells 13. When a USB interface is used, thedata line can be a D+ line and/or D− line in the USB interface.

With respect to contents communicated between the control unit 71 andthe adapter as well as the manner in which the control unit controls thecharging of the multiple cells 13, it is not specifically limited. Forexample, the control unit 71 can communicate with the adapter toexchange the current voltage or current power of the multiple cells 13,to control the adapter to adjust the output voltage or the outputcurrent. As another example, the control unit 71 can communicate withthe adapter to interact with the instant state of the terminal, tonegotiate which charging circuit of the first charging circuit 12 andthe second charging circuit 61 will be used for charging.

In the following, the contents communicated between the control unit 71and the adapter and the manner for controlling the charging process aredescribed in detail with reference to embodiments one through five.

Embodiment One

The control unit 71 performs two-way communication with the adapter todetermine a charging mode to be used, that is, with which the terminalwill be charged. When the control unit 71 determines to charge theterminal with the quick charging mode, the control unit 71 controls theadapter to charge the multiple cells 13 through the first chargingcircuit 12; on the other hand, when the control unit 71 determines tocharge the terminal with the normal charging mode, the control unit 71controls the adapter to charge the multiple cells 13 through the secondcharging circuit 61.

In embodiments of the present disclosure, the terminal is not chargedindiscriminately through the first charging mode but instead willperform two-way communication with the adapter to negotiate whether thequick charging mode can be adopted so as to improve the safety of thequick charging process.

As one implementation, the process that the control unit 71 performstwo-way communication with the adapter to determine the charging mode tobe used can be achieved as follows. The control unit 71 may receive fromthe adapter a first instruction which is configured to inquire theterminal whether to enable the quick charging mode; the control unit 71may send to the adapter a reply instruction responsive to the firstinstruction which is configured to indicate that the terminal agrees toenable the quick charging mode.

Embodiment Two

The control unit 71 performs two-way communication with the adapter todetermine a charging voltage of the quick charging mode.

The control unit 71 may receive from the adapter a second instruction,which is configured to inquire whether a current voltage output by theadapter (that is, the output voltage of the power adapter) is suitableas the charging voltage of the quick charging mode; the control unit 71may send to the adapter a reply instruction responsive to the secondinstruction, which is configured to indicate that the current voltage isappropriate, high, or low. The second instruction can be configured toinquire whether the current voltage output by the adapter matches withthe current voltage of the multiple cells 13, and correspondingly, thereply instruction responsive to the second instruction can be configuredto indicate that the current voltage output by the adapter is matched,high, or low in relative to the current voltage of the multiple cells13.

Embodiment Three

The control unit 71 performs two-way communication with the adapter todetermine a charging current of the quick charging mode.

The control unit 71 may receive from the adapter a third instruction,which is configured to inquire the maximum charging current currentlysupported by the terminal. The third instruction is not limited to theforegoing function however; for example, it can also be configured toinquire a median charging current or any other current value which ishelpful to determine the charging current of the quick charging mode.

The control unit 71 may send to the adapter a reply instructionresponsive to the third instruction, which is configured to indicate themaximum charging current currently supported by the terminal, wherebythe adapter can determine the charging current of the quick chargingmode based on the maximum charging current currently supported by theterminal. The terminal can determine the maximum charging currentcurrently supported by the terminal as the charging current of the quickcharging mode, or determine the charging current of the quick chargingmode after considering the maximum charging current currently supportedby the terminal and its own current output capability.

Embodiment Four

The control unit 71 performs two-way communication with the adapterduring charging using the quick charging mode to adjust the outputcurrent of the adapter.

The control unit 71 may receive from the adapter a fourth instruction,which is configured to inquire the current voltage of the multiple cells13. The control unit 71 may send to the adapter a reply instructionresponsive to the fourth instruction, which is configured to indicatethe current voltage of the multiple cells 13, whereby the adapter canadjust the charging current output by the adapter according to thecurrent voltage of the multiple cells 13.

Embodiment Five

As one implementation, the control unit 71 can perform two-waycommunication with the adapter, whereby the adapter can determinewhether the charging interface is in a poor contact.

As one implementation, the control unit 71 may receive from the adaptera fourth instruction, which is configured to inquire the current voltageof the multiple cells 13; the control unit 71 may send to the adapter areply instruction responsive to the fourth instruction, which isconfigured to indicate the current voltage of the multiple cells 13,whereby the adapter determines whether the charging interface 11 is in apoor contact according to the output voltage of the adapter and thecurrent voltage of the multiple cells. For example, if the currentvoltage of the multiple cells is not equal to or far less than theoutput voltage of the adapter, the charging interface 11 can be deemedas in a poor contact.

Alternatively, as one implementation, the control unit 71 may furtherreceive from the adapter a fifth instruction, which is configured toindicate that the charging interface is in a poor contact.

The communication between the terminal and the adapter will be describedin more detail with reference to specific examples illustrated in FIG.11 . The examples of FIG. 11 are merely for the purpose of assistingthose skilled in the art in understanding the embodiments instead oflimiting the embodiments to the specific numerical or specific scenes.It will be apparent to those skilled in the art that variousmodifications or variations may be made in view of the examplesillustrated in FIG. 11 , and such modifications or variations are withinthe scope of the embodiments of the present disclosure.

Quick Charging Process

As illustrated in FIG. 11 , the quick charging process can include fivestages, that is, Stage 1 to Stage 5.

Stage 1

After the control unit 71 is coupled to a power supply device (or acharging device), the terminal can detect the type of the power supplydevice through the data line D+, D−. When the power supply device isdetected as an adapter, the current received by the terminal may begreater than a preset current threshold I2 (for example, may be 1 A).When the adapter detects that the output current thereof is greater thanor equal to 12 in a preset duration of time (for example, a continuousperiod of time T1), the adapter may assume that the terminal hasfinished the type identification of the power supply device. Thus, theadapter may start handshaking with the control unit 71 and sendInstruction 1 (corresponding to the above first instruction) to thecontrol unit 71 to inquire whether to enable the quick charging mode (orflash charging mode).

When the adapter receives a reply instruction responsive to Instruction1 from the control unit 71, which indicates that the control unit 71does not agree to enable the quick charging mode, the adapter detectsits own output current again. When the output current of the adapter isstill greater than or equal to I2 within the preset continuous durationof time (for example, a continuous time T1), the adapter may sendInstruction 1 to the control unit 71 again to inquire whether to enablethe quick charging mode. The adapter repeats the above operations ofstage 1 until the control unit 71 agrees to enable the quick chargingmode or the output current of the adapter is no longer greater than orequal to 12.

When the control unit 71 agrees to enable the quick charging mode, thequick charging process is enabled and the quick charging communicationprocess proceeds to Stage 2.

Stage 2

The output voltage of the adapter may correspond to multiple levels. Theadapter may send Instruction 2 (corresponding to the above secondinstruction) to the control unit 71 to inquire whether the outputvoltage of the adapter is suitable as a charging voltage for the quickcharging mode. In other words, Instruction 2 is configured to inquirewhether the current voltage output by the adapter matches with thecurrent voltage of the multiple cells 13.

The control unit 71 may send a reply instruction responsive toInstruction 2 to the adapter to indicate that the current voltage outputby the adapter is appropriate, high, or low. For example, when the replyinstruction responsive to Instruction 2 indicates that the currentvoltage output by the adapter is high or low, the adapter can adjust thecurrent voltage for one level and send Instruction 2 to the control unit71 again to inquire whether the voltage currently output by the adapteris suitable as a charging voltage for the quick charging mode. The aboveoperations of Stage 2 will be repeated until the control unit 71determines that the voltage currently output by the adapter is suitableas the charging voltage in the quick charging mode, and the proceduremay proceed to Stage 3.

Stage 3

The adapter may send Instruction 3 (corresponding to the above thirdinstruction) to the control unit 71 to inquire the maximum chargingcurrent currently supported by the control unit 71. The control unit 71may send a reply instruction responsive to Instruction 3 to the adapterto indicate the maximum charging current currently supported by theterminal, and the procedure may proceed to Stage 4.

Stage 4

The adapter determines the charging current of the quick charging modebased on the maximum charging current currently supported by theterminal. The procedure may proceed to Stage 5, that is, aconstant-current stage.

Stage 5

After entering the constant-current stage, the adapter may sendInstruction 4 (corresponding to the above fourth instruction) to thecontrol unit 71 at intervals to inquire the current voltage of themultiple cells 13. The control unit 71 can send to the adapter aresponse message to Instruction 4, to feedback the current voltage ofthe multiple cells 13. Based on the current voltage of the multiplecells 13, the adapter can judge whether the charging interface is in agood contact and whether it is necessary to step-down the output currentthereof. When the adapter judges that the charging interface is in apoor contact, it can send Instruction 5 (corresponding to the abovefifth instruction) to the control unit 71 and then reset to re-enterStage 1.

As one implementation, at Stage 1, when the control unit 71 sends thereply instruction responsive to Instruction 1, data or information ofpath impedance of the terminal can be carried in the reply instructionresponsive to Instruction 1. With aid of the data of path impedance ofthe terminal, the adapter can determine whether the charging interfaceis in a good contact at Stage 5.

As another implementation, at Stage 2, the time elapsed from when theterminal agrees to enable the quick charging mode until when the adapteradjusts the output voltage to an appropriate voltage can be controlledto be within a certain range. When the time exceeds the certain range,the control unit 71 may determine that the quick charging communicationprocess is abnormal and reset to re-enter Stage 1.

As still another implementation, at Stage 2, when the current voltageoutput by the adapter is ΔV (which is about 200-500 Mv) higher comparedwith current voltage of the multiple cells 13, the control unit 71 cansend the reply instruction to Instruction 2 to the adapter to indicatethat the current voltage output by the adapter is appropriate.

As still another implementation, at Stage 4, the adjustment speed of theoutput current of the adapter can be controlled within a certain range;as such, abnormality induced by excessive adjustment speed in thecharging process of the first charging circuit 12 can be avoided.

As still another implementation, at Stage 5, the variation of the outputcurrent of the adapter can be controlled within 5%.

As still another implementation, at Stage 5, the adapter can monitor thepath impedance of the first charging circuit 12 in real time.Specifically, the adapter may monitor the path impedance of the firstcharging circuit 12 based on the output voltage of the adapter, theoutput current, and the current voltage of the multiple cells 13 fedback by the control unit 71. When the path impedance of the firstcharging circuit 12 is greater than the sum of the path impedance of theterminal and the impedance of the charging cable, the adapter mayconsider that the charging interface is in a poor contact and stopcharging with the first charging circuit 12.

As still another implementation, after the quick charging mode isenabled, intervals at which the adapter and the control unit 71 arecommunicated can be controlled to be within a certain range to avoidabnormalities caused by short intervals in the quick chargingcommunication process.

As still another implementation, termination of the quick chargingprocess (or termination of the quick charging mode) may be a recoverableand unrecoverable termination.

For example, when it is detected that the multiple cells 13 are fullycharged or the charging interface is in a poor contact, the quickcharging process can be stopped and reset to re-enter Stage 1; otherwiseif the terminal does not agree to enable the quick charging mode, thequick charging communication process would not enter Stage 2. Herein,this kind of termination of the quick charging process can be referredto as “unrecoverable termination”.

As another example, when the communication between the control unit 71and the adapter is abnormal, the quick charging process is stopped andreset to re-enter Stage 1. When the requirement of Stage 1 is met, thecontrol unit 71 agrees to enable the quick charging mode to restore thequick charging process. Here, this kind of quick charging process can bereferred to as “recoverable termination”.

As another example, when the control unit 71 detects that a certain cellin the multiple cells 13 is abnormal, the quick charging process can bestopped and reset to re-enter Stage 1. After entering Stage 1, thecontrol unit 71 does not agree to enable the quick charging mode. Untileach of the multiple cells 13 returns to normal and meet the requirementof Stage 1, the control unit 71 agrees to enable the quick charging modeto restore the quick charging process. Here, this kind of termination ofthe quick charging process is a “recoverable termination”.

The communication actions or operations illustrated in FIG. 11 aremerely examples. For example, at Stage 1, after the terminal and theadapter are connected, the handshake communication therebetween may alsobe initiated by the control unit 71; that is, the control unit 71 cansent Instruction 1 to inquire the adapter whether to enable the quickcharging mode. When the control unit 71 receives from the adapter areply instruction indicating that the adapter agrees to enable the quickcharging mode, it can charge the multiple cells 13 through the firstcharging circuit 12.

In addition to the operations illustrated in FIG. 11 , after Stage 5, aconstant-voltage charging stage can be further included. That is, atStage 5, the control unit 71 may feed back the current voltage of themultiple cells 13 to the adapter. When the current voltage of themultiple cells 13 reaches a constant-voltage charging voltage threshold,the charging stage may turn to the constant-voltage stage from theconstant-current stage. In the constant-voltage stage, the chargingcurrent gradually decreases and charging will be terminated when thecharging current drops to a certain threshold, and this indicates thatthe multiple cells 13 have been fully charged.

Components illustrated in the figures can be combined or substitutedwithout conflict. For instance, the control unit illustrated in FIG. 10can be combined with the circuit structure 71 illustrated in any of FIG.1 through FIG. 9 .

Those of ordinary skill in the art will appreciate that, the units andsteps of each of the examples described in connection with theembodiments disclosed herein can be implemented in the form ofelectronic hardware or in combination of computer software andelectronic hardware. Whether these functions are implemented in hardwareor software depends on specific applications and design constraints ofthe technical solution. The skilled artisan may use different methods toimplement the described functions for each particular application, butsuch implementations should not be considered as beyond the scope of thepresent disclosure.

It will be apparent to those skilled in the art that, for theconvenience and simplicity of description, the specific processes of thedescribed systems, devices, and units described above may refer to thecorresponding processes in the foregoing embodiments of the method andwill not be described again.

In the embodiments of the present disclosure, it will be appreciatedthat, the system, device, and method disclosed can be implemented inother ways. For example, the device embodiments described above aremerely illustrative; the division of the units is only a logicalfunction division, and the units can be divided into other ways duringthe actual implementation; for example, multiple units or components canbe combined or can be integrated into another system, or some featurescan be ignored or not implemented. In addition, the coupling or directcoupling or communication connection illustrated or discussed betweeneach other can be an indirect coupling or indirect communicationconnection via some interface, device, or unit, and it can be inelectrical, mechanical, or other forms.

The units illustrated as separate components can or cannot be physicallyseparated, and the components displayed as units can or cannot bephysical units, that is to say, the units or components can be locatedin one place, or can be distributed over multiple network elements. Someor all of these units can be selected according to actual needs toachieve the purpose of the embodiments of the present disclosure.

In addition, the functional units in various embodiments of the presentdisclosure can be integrated in one processing unit. It is also possiblethat the individual units are physically present individually, or, it isalso possible to integrate two or more units into one unit.

When implemented in the form of a software functional unit and sold orused as a stand-alone product, the functionality can be stored in acomputer readable storage medium. Based on such understanding, technicalsolutions of the present disclosure in essence or in part, or part ofthe technical solutions which contributes to the related art, can beembodied in the form of a software product. The software product can bestored in a storage medium and include several instructions, which isconfigured to cause computer equipment (such as a personal computer, aserver, or network equipment) to execute all or part of the method stepsof the embodiments of the present disclosure. The aforementioned storagemedium includes U-disk, mobile hard disk, Read-Only Memory (ROM), RandomAccess Memory (RAM), disk, CD, or various media that can store programcode.

What is claimed is:
 1. A terminal, comprising: a charging interface; afirst charging circuit, coupled with the charging interface, andconfigured to receive an output voltage from an adapter and apply theoutput voltage to both ends of multiple cells connected in series in theterminal to charge the multiple cells without voltage converting; and asecond charging circuit comprising a step-up circuit, the step-upcircuit having a first end coupled with the charging interface and asecond end coupled with the multiple cells, wherein the step-up circuitis configured to receive the output voltage of the adapter via thecharging interface, step up the output voltage of the adapter to asecond voltage, and apply the second voltage to both ends of themultiple cells for charging; and the output voltage of the adapter isreceived by the second charging circuit being less than an overallvoltage of the multiple cells, the second voltage being greater than theoverall voltage of the multiple cells; wherein the first chargingcircuit is operable in a quick charging mode, the second chargingcircuit is operable in a normal charging mode, and a charging speed ofthe terminal in the quick charging mode is higher than the chargingspeed of the terminal in the normal charging mode; wherein the terminalfurther comprises an equalization circuit, the equalization circuit iscoupled with the multiple cells and is configured to equalize voltagesamong each cell of the multiple cells; wherein the terminal furthercomprises a control unit configured to: perform two-way communicationwith the adapter to determine a charging mode; and switch between thefirst charging circuit to charge the multiple cells through the firstcharging circuit upon determining that the terminal will be charged withthe quick charging mode and the second charging circuit to charge themultiple cells through the second charging circuit upon determining thatterminal will be charged with the normal charging mode.
 2. The terminalof claim 1, further comprising: a step-down circuit, having input endsand an output end, the input ends being coupled with both ends of themultiple cells and configured to convert an overall voltage of themultiple cells into a first voltage V1, wherein a≤V1≥b, a represents theminimum operating voltage of the terminal, and b represents the maximumoperating voltage of the terminal; and a power supply circuit, coupledto the output end of the step-down circuit and configured to supplypower to system components of the terminal based on the first voltage.3. The terminal of claim 2, wherein the step-down circuit comprises acharge pump, and the first voltage is 1/N of the overall voltage of themultiple cells, and wherein N represents the number of cells included inthe multiple cells.
 4. The terminal of claim 1, wherein the firstcharging circuit is further configured to receive an output current fromthe adapter, and wherein the output current is one of a pulsating directcurrent and an alternating current.
 5. The terminal of claim 1, whereinthe first charging circuit is operable in a charging mode ofconstant-current mode.
 6. The terminal of claim 1, wherein the outputvoltage of the adapter received by the second charging circuit is 5V. 7.The terminal of claim 1, wherein the charging interface comprises a dataline, and the control unit is configured to perform two-waycommunication with the adapter via the data line.
 8. The terminal ofclaim 1, wherein the control unit configured to perform the two-waycommunication with the adapter is further configured to: receive a firstinstruction from the adapter, the first instruction being configured toinquire the terminal whether to enable the first charging mode; and senda reply instruction responsive to the first instruction to the adapter,the reply instruction responsive to the first instruction beingconfigured to indicate that the terminal determines to enable the quickcharging mode.
 9. The terminal of claim 7, wherein the control unitconfigured to perform the two-way communication is further configuredto: perform the two-way communication with the adapter to determine acharging voltage of the quick charging mode.
 10. The terminal of claim9, wherein the control unit configured to perform the two-waycommunication to determine the charging voltage of the quick chargingmode is further configured to: receive a second instruction from theadapter, the second instruction being configured to inquire whether theoutput voltage of the adapter is suitable as the charging voltage of thequick charging mode; and send a reply instruction responsive to thesecond instruction to the adapter, the reply instruction responsive tothe second instruction being configured to indicate that the outputvoltage is one of appropriate, high, and low.
 11. The terminal of claim7, wherein the control unit configured to perform the two-waycommunication is further configured to: perform the two-waycommunication with the adapter to determine a charging current of thequick charging mode.
 12. The terminal of claim 11, wherein the controlunit configured to perform the two-way communication with the adapter todetermine the charging current of the quick charging mode is furtherconfigured to: receive a third instruction from the adapter, the thirdinstruction being configured to inquire the maximum charging currentcurrently supported by the terminal; and send a reply instructionresponsive to the third instruction to the adapter, the replyinstruction responsive to the third instruction being configured toindicate the maximum charging current currently supported by theterminal, wherein the adapter determines the charging current of thequick charging mode according to the maximum charging current currentlysupported by the terminal.
 13. The terminal of claim 7, wherein thecontrol unit configured to perform the two-way communication with theadapter via the data line to control the charging of the multiple cellsis further configured to: perform the two-way communication with theadapter during charging with the quick charging mode to adjust an outputcurrent of the adapter.
 14. The terminal of claim 13, wherein thecontrol unit configured to perform the two-way communication with theadapter to adjust the output current of the adapter is furtherconfigured to: receive a fourth instruction from the adapter, the fourthinstruction being configured to inquire a current voltage of themultiple cells; and send a reply instruction responsive to the fourthinstruction to the adapter, the reply instruction responsive to thefourth instruction being configured to indicate the current voltage ofthe multiple cells, wherein the adapter adjusts the output current ofthe adapter according to the current voltage of the multiple cells. 15.The terminal of claim 1, further comprising: a power supply circuit,having input ends coupled with both ends of a single cell of themultiple cells and supply power to devices inside the terminal based ona voltage of the single cell coupled with the power supply circuit. 16.A device, comprising: a charging interface; a cell unit comprisingmultiple cells connected in series; a first charging circuit, coupledwith the charging interface and configured to receive an output voltagefrom a charging device and apply the output voltage to both ends of thecell unit for charging the multiple cells; a second charging circuit,coupled in parallel with the first charging circuit and configured toreceive the output voltage from the charging device via the charginginterface, step up the received output voltage, and apply a step-upoutput voltage to the both ends of the cell unit for charging themultiple cells, wherein the first charging circuit is capable of beingoperated in a quick charging mode, the second charging circuit iscapable of being operated in a normal charging mode, and a chargingspeed of the device in the quick charging mode is greater than thecharging speed of the device in the normal charging mode; anequalization circuit, coupled with the multiple cells and configured toequalize voltages among each cell of the multiple cells; and a controlunit, configured to: perform two-way communication with the adapter todetermine a charging mode; and switch between the first charging circuitto charge the multiple cells through the first charging circuit upondetermining that the terminal will be charged with the quick chargingmode and the second charging circuit to charge the multiple cellsthrough the second charging circuit.
 17. The device of claim 16, whereinthe multiple cells comprises a main cell and at least one secondarycell, the equalization circuit comprises at least one load eachconnected at both ends of each of at least one secondary cell to consumethe power of the secondary cell, such that the power of the secondarycell is consistent with the main cell.